1. Field of the Invention
The present invention relates to the placement, design and use of centralized, aggregating, freight container cleaning, maintenance, repair, and redistribution facilities in particular to improve the supply chain management of railroad freight car assets and the timely redistribution of laden and unladen cars to points on a railroad network.
2. Description of Related Art
In current railroad freight traffic operations involving movement of freight cars, stress is placed on path planning to implement the efficient transit of laden cars from loading points to delivery destinations (consignees). Once they have been unloaded at the consignees, the empty cars must be moved to the next loading point before they can be re-used.
One problem preventing the efficient movement of freight cars is congestion in the rail transportation system. In existing industry operating practice for rail cars it is customary to generate the transit path for return of the unladen cars by simply reversing the path of the loaded cars. Relative to the planning which is applied to the efficient delivery of loaded cars, insufficient little attention has been paid to exploring alternative and possibly more efficient paths for the movement of the unladen cars. Instead, the movement of unladen (empty) railway freight cars are not seen as “revenue generating moves” by the rail carriers, and therefore the transit of empty freight cars back to the loading point is generally of lesser priority than the movement of outbound laden cars. One result is an excess number of unladen freight cars which leads to congestion, which further delays the transit times for unladen freight cars returning to loading points and the transit times of laden cars moving to consignees.
In one attempt to reduce the number of cars on the railroad system, rail carriers often charge demurrage for cars that cannot be placed within a shipper's facility. These charges are punitive in nature and do not solve a fundamental problem of a lack of railroad infrastructure.
Another attempt to alleviate the congestion is through the use of third party capital to help build railcar storage infrastructure. However, most of these applications have been customer-specific or have focused on the storage of loaded cars and have done little to improve overall rail system velocity or rail carrier service plan improvements involving empty rail cars. Additionally, neither the shippers nor the rail carriers operate within a capital allocation model that addresses the problem of congestion. The shippers generally allocate new capital expenditures towards increasing their manufacturing capacity. Rail carriers generally allocate capital expenditures towards the purchase of new rolling stock/equipment and improving the mainline track infrastructure. The shippers want to focus on their core competency of making more product and the rail carriers want to focus on their core competency of the line-haul freight movement.
Within the existing business model, as described above, a primary concern in current supply chain management is the resulting congestion due to empty freight cars. A secondary concern is the build-up of product inventory associated with the congestion in the overall railroad system. Therefore, it is desirable to improve the supply chain management of rail cars. It is furthermore, desirable to reduce the congestion on trackage in the rail transportation system. It is further desirable to minimize the total number of cars within the rail transportation system.
A second problem affecting the movement of freight cars back to the loading points is due to the functions a freight car performs. Considered as an economic asset, an important feature of a railroad freight car is that it fulfills two separate functions, being both a medium of transportation, and a storage vessel. The confounding of these separate functions and possible conflicts between them must be considered in any economic analysis of the efficiency of utilization of such assets. This is a real need and not a purely academic issue, since, in actual practice, the cars are used in both modes and the producers and consumers of the product carried by the car actively exploit both functions.
The railroad carrier naturally focuses on the transportation function, and would prefer that system trackage be used minimally for the storage function, since such usage is not consistent with the carrier's desire to focus on the line-haul movement of the car. As well, storage services alone provide a reduced economic benefit to the railroad when compared to their line-haul operations, and may cause traffic congestion in existing classification yards.
In contrast to the railroad carriers' handling of freight cars for transportation of products, manufacturers and producers derive value from the freight cars as storage units. While the value of the transportation function of a rail car may be obvious, the value of its storage function must be considered in more detail. By the nature of the bulk transportation capability of railroad freight operations, manufacturing and production facilities that use railroad transportation are usually operations generating products in large quantities. Such production facilities often operate continuously 24 hours a day and 7 days a week, and cannot be started or stopped without incurring significant costs. For this reason, it is important for the plant operator to have available empty storage containers at all times ready to receive the product. It is common practice in many manufacturing operations for the production facility to use the railroad freight cars for such storage. Doing so avoids not only the capital investment in fixed on-site storage space, but also the ongoing cost of transferring the product from fixed storage to railroad cars.
The same logic applies at the receiving (i.e., consignee) end of the freight path. The users or consumers are typically operations, which must be assured of continuous availability of the product, often as feedstock to a manufacturing operation. It is common to use the loaded railroad cars as reservoirs from which material can be withdrawn as needed to keep the manufacturing operation running. The differing viewpoints and priorities of the railroad carriers and their customers may be a source of significant friction, reducing the economic performance of the distribution system as a whole.
A salient feature of this production, distribution and consumption model is that, while the production and consumption functions are generally steady-stream flow processes, the railroad transportation function is a batch process. Release rates of the unladen cars from the consignees have a high degree of variability so as to create unpredictability in the return of cars back to a producer. This erratic flow and supply of unladen cars is perpetuated by the rail carriers as they attempt to place all available cars back at the production facility and keep the cars from creating congestion within the carriers' classification yards. Therefore, under current distribution models, a plant may be lacking cars one day, then not have enough storage for inbound cars the next day. Due to the erratic nature of the empty car supply, most producers hold on-site, or ask the rail carriers to hold locally, a sufficient safety stock of cars to sustain manufacturing operations for several days, and additional quantities to span weekends or periods of rail service interruptions and shutdowns. Holding a high amount of safety stock inventory is necessitated only due to the high degree of variability in the flow of cars in the current business model. To match the manufacturing steady-stream flow processes to the variability of rail carrier performance, and to be assured of the availability of empty cars at the production plant and loaded cars at the consignee, it has been a fundamental necessity of the operators of the car fleets to increase the size of the fleets. In fact, most plastic resin producers, as an example, agree that they have an excess number of cars in their fleets to accommodate the variability in the clean car supply chain. The excess of cars further adds to the congestion within the rail carrier facilities such that the overall rail system velocity is negatively impacted. Building fleet sizes to levels greater than would optimally be required may address the acute operating need but, this practice requires capital, not just for the cars themselves, but also for storage yards and the associated infrastructure to be used for storage of the freight containers. The increase in size of the fleets also poses problems for the railroad carriers, since, inevitably, the number of cars on their tracks—in storage, in—transit, and in classification yards—increases commensurately. The resulting congestion increases the cost of transportation, causes inconsistent rail service to occur and results in a sub-optimized supply chain. Inconsistent rail service and reduced rail system velocity may motivate the producers/manufacturers to acquire yet more cars, further adding to the problem. It is therefore desirable to minimize the number of freight cars in the transportation system, while at the same time providing enough freight cars at manufacturers' and producers' facilities to prevent work stoppage at those facilities. It is further desirable to provide buffers and points of aggregation in the rail system so that producers can employ just-in-time inventory management techniques to the distribution of their products. These points of aggregation will serve to remove the variability in the flow of unladen cars coming back to manufacturers' facilities. As well, for laden cars, these facilities will serve as storage-in-transit inventory control points and is consistent with the theory of “forward deployed inventory.”
A second aspect of railroad traffic operations that negatively affects the supply chain of cars is the handling of freight cars in railyards. An important cost factor in railroad freight operations is the process of sorting or switching cars, normally performed in a classification yard. This is necessary since a train consist is generally heterogeneous, with differing types of cars destined for differing final destinations. Each train consist is constructed by assembling cars headed for the same next way point in their transit plan, but not necessarily the same final destination. At each waypoint the train consist may be reclassified and the cars re-sorted to be assembled into a consist to proceed to the next waypoint. Clearly it is desirable to minimize the classification process and reduce the total number of handling events. This is done by grouping together cars which are headed for the same geographic area, so that at successive classification yards the group can be sorted as a single entity rather than handling each car individually. The process of grouping cars headed for the same final destination is termed “blocking”, and is very desirable and well accepted as a method for improving the efficiency of railroad operations. Moving a series of blocked cars to the same destination in the rail system reduces the costs incurred by the rail carrier in their terminal/yard operations and increases the velocity of the overall rail.
However, important classes of freight cars are dedicated to the transportation of specific products, and such cars are frequently capital assets of the product manufacturer. The distinctions between cars relate not just to the mechanical design to handle differing materials such as solids or liquids, but to distinctions made between cars of identical design in order to address possible contamination of a shipment from traces of material remaining in a car from a preceding load. For this reason, even cars of identical design are frequently not treated as generic, homogeneous assets. In existing practice, many cars are dedicated to specific finished goods, and even within a specific manufacturing facility where the products are generated. Therefore, because of these product/container segregations and the rail carriers' practice of reverse routing of the cars, the containers are generally returned unladen to the same geographic location from which they originated their last loaded movement. The combination of reverse routing of the car, combined with product/container segregation, makes the homogeneous use of the assets problematic, even when the containers are intended for the same service/use and may even belong to the same manufacturer operating multiple production facilities.
An example of the shortcomings of the present practices for railroad traffic operations is the production and consumption of polymer resins. The majority of the production of polymer resins in the United States occurs along the Gulf coast of Texas. A polymer resin producer will typically generate production of a specific type of resin and load the output into covered hopper rail cars for transport to consignees, a large number of which are manufacturers located in the Northeast portion of the United States. Different types of polymer resins cannot be intermixed, as even a small amount of product contamination may negatively impact a consignee's manufacturing process.
The laden freight cars will make their transit from the production region to the manufacturers or consumption regions. Path planning is utilized for the outbound portion of the trip. See, U.S. Pat. Nos. 5,794,172; 5,623,413; 5,828,979; 5,836,529; and 5,797,113 (incorporated by reference). After unloading at the consignees, the empty cars are generally returned to the originating production plant using the same outbound routing. The velocity of inbound rail car movements reduces greatly as the cars near the loading points—going through multiple exchanges, classifications, and blocks before being delivered back to a shipper's plant site. As can be appreciated, this transportation system is inefficient, costly, and undesirable. Inbound empty transit times can be 10-25% longer than outbound loaded times. It is therefore desirable to provide a system for the efficient return of unladen cars back to the originating production plants.
Furthermore, nearly all plastics producers clean their hopper cars after each trip and prior to loading. Such railcar cleaning is typically done at the plant site, but occasionally through off-site shops or repair facilities. The cleaning procedures vary little from producer to producer and could be standardized. Many plastics producers also have in-plant rail car maintenance shops, which may have limited repair capabilities and little capacity. These existing rail car maintenance operations may lack uniformity in processes and procedures, quality of work, and record keeping. It is therefore desirable to provide a system for standardized cleaning, inspection, repair and maintenance of railcars, along with reliable record keeping.